Canon EF 28mm f1.8 USM Review for Video and Film
Can be had for around $400 new on amazon, or $250-$350 used
This lens is in the Canon EF prime USM family along with the 50mm f1.4 USM, 85mm f1.8 USM, etc. It has a similar build to those lenses, being made of both metal and plastic and being small and lightweight but also offering a wide aperture.
Honestly there's not much of a reason to buy this lens for video unless you need the f1.8 aperture. Other than that, the 28mm framing is covered by most f2.8 or f4 zooms like the Canon EF 24-105mm f4. There are a few reasons to get this lens, however, and I'll go over them below.
First of all, the build quality is surprisingly good. It has a metal shell and mount and is pretty heavy. The filter mount is plastic but is built into the body of the lens so it can take a beating, which is how it should be made. The Canon EF 50mm f1.4 USM has a filter ring that protrudes from the body of the lens and is very fragile. That was one of the reasons I got rid of mine and picked up the new STM f1.8 version (even though the STM lens still has a lens barrel that protrudes, it is a much cheaper lens to replace).
Another reason I liked this lens is because it gives me a nice normal focal length for a cropped body camera like the Canon 60d. I wanted to shoot with a cropped body camera because sometimes the shallow depth of field of full frame is just too extreme and pulling focus is tough. This 28mm lens gives me an equivalent of around 45mm on full frame, so basically have a nice 50mm f1.8 lens for my 60d.
Pulling focus is great on this lens as it has a nice focus ring that is smooth and solid, better than the 50mm f1.4.
On full frame this lens will give you a nice wide frame to use in dark situations with the f1.8 aperture, so it sort of pulls double duty on FF and cropped which is one of the mains reasons I got it.
The final reason to get this lens is because it has f1.8. That's a huge difference from an f4 zoom and even an f2.8 zoom. Instead of shooting at ISO 1600 with an f4 you'll be able to go to ISO 800 or less at f1.8. This makes a big difference for cropped sensor cameras since at ISO 1600 you'll run into lots of digital noise. On Full frame it's less of an issue.
I imagine this lens would also be a good choice for smaller sensor cameras like a Black Magic Cinema Camera, as long as you have the ability to electronically change the aperture, which I believe you do with the BMCC.
On other small sensor cameras like a Panasonic GH4, you'll be out of luck changing the aperture so you'd be better off with a different lens, like a Nikon manual focus lens or any lens with an aperture ring, like a cinema lens that's made for filmmaking.
Image wise the Canon EF 28mm f1.8 will be a bit soft wide open, getting sharp at f2.8 and smaller apertures. At f1.8 you'll also see some Chromatic Aberrations, but nothing that really detrimental in every day use. It's a great lens and much better than other wide angle primes I've used like Nikon's older 28mm f2.8 lenses.
Other 28mm and wide options
I've owned and used the Canon EF 28mm f2.8 but it really became redundant with all of the f2.8 zoom out there. Between Canon, Sigma and Tamron you're likely to find a better option like the Tamron 28-75mm f2.8 which I use and enjoy.
Canon EF 35mm f1.4L - This lens looks like it'd be great but really its strengths are more fitting for photography in my opinion. For video it'd be great if you have one, but for a lot less money I'd just get the 28 f1.8 or a zoom. At f1.4 nothing is in focus and you'll have a hard time pulling focus and even if you get your subject in focus it won't look sharp due to the shallow DOF.
Zeiss Primes - Never used them. They are probably great, but also again these lenses are designed for photography so don't expect them to be perfect for cinematography. Nikon and Canon primes aren't much worse than these image-wise and they're usually less expensive and offer more versatility but lesser build quality. Primes in general will deliver better quality but you'll have to change them out whereas a good zoom might deliver slightly less quality or smaller max aperture but you can run and gun with one lens.
Nikon 28mm f2.8 - Manual focus or auto focus, Nikon's 28mm f2.8 doesn't have the best reputation. I had one myself and it was really pretty bad. I could get decent photos from it on my 5D but for video it just wasn't sharp and it rendered a bad image. There's something about certain lenses that aren't good that can ruin an image, and my copy of the Nikon 28mm f2.8 (manual focus AIS) did just that. I'm sure other copies of the same lens might be better than the one I had. It even made the digital noise at high ISOs look worse. This is where quality optics do help your image. Again, it depends on the look you're after and these effects from an older lens might be something you want. It's up to you. The Nikon 28mm f1.8 is another animal altogether that I've not personally used, but I imagine it's great, although very big and heavy for a prime.